Re: Unsymmetrical rotation

Blagoj Kupev <[email protected]>
Newsgroups gmane.comp.lib.cairo
Message-ID <CAB=Grm1fYL=3iK0n8sOSvJzWwzLZTXQWA=RoEHkgvd64vSPzDQ@mail.gmail.com>
Hello,
Does anyone else have any other idea? Can this be a bug in cairo?
Best regards,
Blagoj

On Sun, Mar 3, 2013 at 9:59 PM, Blagoj Kupev <[email protected]> wrote:

> Hello,
> Already tried, and does not work... as i can understand the documentation
> the functions cairo_translate and cairo_rotate only modify the current
> transformation matrix and then the transformation is applied when the
> function cairo_set_source_surface is called. Then as i understand,
> cairo_set_source_surface is doing additional matrix transformation with the
> x and y offsets prior the matrix is executed.
>
> It seems that:
>
>    cairo_translate (cr, x_origin, y_origin);
>    cairo_rotate (cr, (2*3.14*angle/360));
>    cairo_set_source_surface(cr, surf1, x, y);
>
> Is the same as:
>
>    cairo_translate (cr, x_origin, y_origin);
>    cairo_rotate (cr, (2*3.14*angle/360));
>    cairo_translate (cr, x, y);
>    cairo_set_source_surface(cr, surf1, 0, 0);
>
> Thanks,
> Blagoj
>
> On Sun, Mar 3, 2013 at 9:37 PM, Bill Spitzak <[email protected]> wrote:
>
>> On 03/03/2013 06:33 AM, Blagoj Kupev wrote:
>>
>>     cairo_translate (cr, x_origin, y_origin);
>>>    cairo_rotate (cr, (2*3.14*angle/360));
>>>
>>>    cairo_set_source_surface(cr, surf1, -x_origin+x_offset, -y_origin);
>>>    cairo_paint(cr);
>>>
>>
>> I think this will work:
>>
>>
>>     cairo_translate (cr, x_origin, y_origin);
>>     cairo_rotate (cr, (2*3.14*angle/360));
>>     cairo_translate (cr, x_offset, 0);
>>     cairo_set_source_surface(cr, surf1, -x_origin, -y_origin);
>>
>> --
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>> [email protected]
>> http://lists.cairographics.**org/mailman/listinfo/cairo<http://lists.cairographics.org/mailman/listinfo/cairo>
>>
>
>

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